Control unit for a battery system

Abstract

A control unit for a battery system, comprising: a microcontroller configured to generate a first control signal; a monitoring unit configured to generate a fault signal indicative of the operational state of the microcontroller; a first signal source configured to generate a state signal indicative of a system state; a comparator circuit configured to generate an intermediate control signal based on a first control signal and a fault signal; the comparator circuit further comprising a comparator node, the comparator circuit configured to transmit the intermediate control signal to the comparator node; wherein the first signal source is connected to the comparator node to transmit the state signal to the comparator node; the comparator circuit further comprises a comparator connected to the comparator node and configured to generate a switch control signal based on a voltage on the comparator node and based on a threshold voltage.

What is claimed is: 
     
       1. A control unit for controlling a power switch of a battery system, comprising:
 a microcontroller configured to generate a first control signal; 
 a monitoring unit configured to detect an operational state of the microcontroller and configured to generate a fault signal indicating the operational state of the microcontroller; 
 a first signal source configured to generate a state signal indicating a system state; and 
 a comparator circuit configured to receive the first control signal and the fault signal and configured to generate an intermediate control signal based on the first control signal and the fault signal, 
 the comparator circuit comprising a comparator node, wherein the comparator circuit is configured to transmit the intermediate control signal to the comparator node, 
 wherein the first signal source is connected to the comparator node to transmit the state signal to the comparator node, 
 wherein the comparator circuit further comprises a comparator connected to the comparator node and is configured to generate a switch control signal for controlling the power switch based on a voltage of the comparator node and based on a threshold voltage, and 
 wherein a first input of the comparator is connected to the comparator node and a second input of the comparator is configured to receive the threshold voltage. 
 
     
     
       2. The control unit of  claim 1 , wherein the microcontroller is configured to generate a second control signal and the comparator circuit is configured to receive the first control signal, the second control signal and the fault signal, and configured to generate an intermediate control signal based on the first control signal, the second control signal and the fault signal and configured to transmit the intermediate control signal to the comparator node. 
     
     
       3. The control unit of  claim 2 , wherein the comparator node is interconnected between a first resistor and a second resistor, wherein the first resistor is connected to the microcontroller via a first control line to receive the first control signal, wherein the second resistor is connected to the microcontroller via a second control line to receive the second control signal. 
     
     
       4. The control unit of  claim 2 , further a latch unit interconnected between the comparator node and the microcontroller,
 wherein a first input of the latch unit is connected to the microcontroller to receive one of the first and second control signals, and a second input of the latch unit is connected to the monitoring unit to be controlled by the fault signal, and 
 wherein the latch unit is configured to latch a previous output, when the latch unit receives a fault signal indicative of a fault state of the microcontroller. 
 
     
     
       5. The control unit of  claim 2 , wherein an AND-operator is interconnected between the comparator node and the microcontroller,
 wherein a first input of the AND-operator is connected to the microcontroller to receive one of the first and second control signals, and a second input of the AND-operator is connected to the monitoring unit to receive the fault signal. 
 
     
     
       6. The control unit of  claim 5 , further comprising a time delay unit interconnected between the latch unit and the microcontroller and/or interconnected between the AND-operator and the microcontroller, wherein the time delay unit is configured to delay the first and/or the second control signal by a predetermined time. 
     
     
       7. The control unit of  claim 1 , wherein the comparator circuit comprises a diode interconnected between the first signal source and the comparator node. 
     
     
       8. The control unit of  claim 1 , wherein the comparator node is connected to the microcontroller to receive a diagnostic signal indicative of a present voltage on the comparator node. 
     
     
       9. The control unit of  claim 1 , comprising a first timer connected to the monitoring unit to receive the fault signal and configured to be activated by fault signal, when the fault signal is indicative of a fault state of the microcontroller, wherein the first timer is connected to a second signal source and configured to activate the second signal source after a first time period, the second signal source further connected to the comparator node. 
     
     
       10. The control unit of  claim 9 , further comprising a second timer connected to the monitoring unit to receive the fault signal and configured to be activated by the fault signal, in response to the fault signal indicating a fault state of the microcontroller, wherein the second timer is configured to shut down a power supply of the comparator, in response to the second time period being lapsed, wherein the second time period larger than the first time period. 
     
     
       11. The control unit of  claim 2 , wherein the intermediate signal is lower than the threshold voltage, in response to the first and/or the second control signal being generated in response to a detected system fault; and the state signal is lower than the threshold voltage, in response to the state signal indicating a system fault. 
     
     
       12. The control unit of  claim 1 , wherein the comparator comprises a third resistor interconnected between the output of the comparator and the first input of the comparator. 
     
     
       13. The control unit of  claim 1 , wherein the comparator comprises a supply voltage connected in series with a fourth resistor and a fifth resistor, wherein the second input of the comparator is connected to a node interconnected between the fourth resistor and the fifth resistor. 
     
     
       14. A battery system comprising a plurality of battery cells electrically connected between a high voltage node and a low voltage node, a power switch interconnected between the high voltage node and the low voltage node, and a control unit according to  claim 1 , wherein the output of the comparator of the control unit is connected to a power switch driver of the power switch. 
     
     
       15. An electric vehicle including a battery system according to  claim 14 .